Field of the Invention
The present invention relates to an image forming apparatus and a remaining toner amount estimation method, and, for example, relates to processing for estimating the amount of a coloring material that has been consumed.
Description of the Related Art
Electrophotographic image forming apparatuses such as multifunction peripherals, printers and the like sometimes have a remaining toner amount display function for displaying how much toner is left, in order to inform the user when it is time to replace a toner bottle or a toner cartridge. In order to realize remaining toner amount display, the amount of toner consumed up to the current point in time needs to be accurately measured or estimated, one means of which is a consumed toner amount estimation method proposed in Japanese Patent Laid-Open No. 11-174909.
Japanese Patent Laid-Open No. 11-174909 proposes a technique that involves a pulse accumulator accumulating the number of laser drive pulses as consumed toner amount indicator data, and estimating the consumed toner amount by applying correction values relating to image type, remaining toner amount and humidity to the accumulated number of laser drive pulses to accurately control toner supply. Here, the correction values are determined depending on image type which includes character/line mode, photograph mode and map mode.
Thus, in the conventional technology, the correction values that are applied to the consumed toner amount are determined from frequently-used density regions, the number of screen lines and the like in association with the image type. However, analog printer engine controls which are adjusted after the accumulated density is calculated by the pulse accumulator and affect the consumed toner amount are not subject to correction. This could possibly result in the estimation accuracy being unable to track the actual amount of toner consumed in the case where printer engine controls change.